Devices and methods for intrabody surgery

ABSTRACT

A catheter assembly which is combined with a radiofrequency (RF) electrosurgical instrument includes a catheter body and a vacuum source disposed at the distal end of the catheter. Multiple active electrodes are provided for transmitting electrical signals and to produce electrosurgical effects adjacent to the active electrodes for tissue cutting. At least one passive electrode is disposed at the front end of the body in closely spaced relationship relative to the active electrodes. The active electrodes and the passive electrode optimally cover a predetermined ablation area. The electrodes are spaced from inner walls of the hollow interior, and openings are provided to aspirate debris of ablation into and through the hollow interior of the body by the low-pressure zone.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is continuation-in-part Application of patentapplication Ser. No. 16/192,781 filed Nov. 15, 2018 which claimspriority of Provisional Patent Application Ser. No. 62/586,654 filed bythe Applicant on Nov. 15, 2017 and Provisional Patent Application Ser.No. 62/680,260 filed by the Applicant on Jun. 4, 2018, the entiredisclosure of these applications is hereby incorporated by reference.

FIELD OF THE INVENTION

The devices and methods of the invention generally relate to intrabodysurgery and to treatment of occluded body lumens. In particular, thepresent devices and methods relate to removal of the occluding materialfrom the blood vessels as well as other body lumens.

BACKGROUND OF THE INVENTION

The devices and methods of the invention are applicable for varioustypes of intrabody surgery including, but not limited to cutting,breaking, coagulation, vaporization of any body tissue (including butlimited to soft tissue includes tendons, ligaments, fascia, skin,fibrous tissues, fat, and synovial membranes, etc.; and muscles, nervesand blood vessels (which are not connective tissue) as well as hardtissue/bone and connective tissue, etc.) which involves reaching thetargeted tissue through body channels including but not limited to bloodvessels, ureter, oesophagus, stomach and duodenum(esophagogastroduodenoscopy), small intestine (enteroscopy),largeintestine/colon (colonoscopy, sigmoidoscopy) or incision or cutthrough the body tissues (laparoscopic surgery) or similar.

Although devices and methods for removal of the occluding material fromthe blood vessels as well as other body lumens are discussed below ingreater detail, it should be absolutely clear that this is one of manypossible applications of the invention. In fact, devices and methods ofthe invention are applicable to many types of intrabody surgery, asidentified above.

Cardiovascular diseases frequently arise from the accumulation ofatheromatous material on the inner walls of vascular lumens,particularly arterial lumens of the coronary, peripheral and othervasculature, resulting in a condition known as atherosclerosis.Atheromatous and other intra-vascular deposits restrict blood flow andcan cause ischemia which, in acute cases, can result in myocardialinfarction or a heart attack, stroke or aneurysm. Atheromatous depositscan have widely varying properties, with some deposits being relativelysoft and others being fibrous and/or calcified. In the latter case, thedeposits are frequently referred to as plaque. Atherosclerosis occursnaturally as a result of aging but may also be aggravated by factorssuch as diet, hypertension, heredity, vascular injury, and the like.

Atherosclerosis can be treated in a variety of ways, including drugs,bypass surgery, and a variety of catheter-based approaches which rely onintravascular widening or removal of the atheromatous or other materialoccluding the blood vessel. Specific catheter-based interventionsinclude angioplasty, atherectomy, RF ablation cutting devices, stenting,and the like. For the most part, however, this can be difficult orimpossible in tortuous regions of the vasculature. Moreover, thecatheters used for these interventions are often introduced over aguidewire, and the guidewire is placed across the lesion prior tocatheter placement. Initial guidewire placement can be equally difficultif it needs to be placed through a long and multidirectionalvasculature. This is especially so when the lesion occludes the bloodvessel lumen to such an extent that the guidewire cannot be advancedacross the lesion.

Occlusion in a blood vessel can be caused by a variety of materials fromhard bone like calcium deposits to soft blood clot or piece of fattydeposit. Multiple type occlusions may be present in the same vessel.Currently different tools are used to remove different types ofocclusion. Surgeons may need to remove one type of catheter and replaceit with another one in order to work with different occlusion types.This extends treatment time, substantially raises cost, and increaserisk for a patient. The inventions provide a more optimal and completesolution to this problem which include means to analyze the type ofocclusion material present and then adapt the function of the occlusionremoval device accordingly. Furthermore, the invention provides acombinational arrangement which enables sergeants to successfully workwith different occlusion types without the need to remove one type ofcatheter/cutting tool and replace it with another one.

In prior art, there are known rotational atherectomy systems utilizingdiamond drill tips/burrs to sand hard calcified occlusions to very smallparticles. While there are some discussions that the particles producedfrom 20 μm diamond—tipped burr that ablates plaque into micro-particlesare smaller in size (˜5 μm) than a red blood cell (8 μm), it is alsoknown that larger particles of debris, produced when occlusion is beingbroken, are generated. Such larger particles can block blood capillariesand cause serious side effects. However, even when the occlusionparticles are as small as blood cells, their presence in the bloodstream may present a potential risk. Especially if such particles areaccumulated at the essential body tissues, causing malfunctioning of thevital body organs. Visible accumulation of even smaller particles, forexample tattoo ink particles (less than 1 μm⁽⁹⁾), is well known. Thetattoos particles accumulation (tattoo) is well known to be permanent orat least long term. Since the tattoo ink is inserted into the skin, itmostly stays in the dermis. Thus, impact of the ink particles on othertissue and organs is localized. On the other hand, since the particlesgenerated during the occlusion destruction can be carried out throughthe blood stream to the vital body organs, proper management of suchbecome important. Some of the rotational atherectomy catheters havebuilt-in arrangements with active aspiration to remove debris from theblood stream and evacuate the debris through the catheter or catch theminto a separately inserted catch-basket downstream the blood vessel postocclusion zone. However, these aspiration (debris evacuation)arrangements are not optimally designed to remove all or most of suchdebris particles. The inventions propose more optimal and completesolutions to this problem.

The prior art solutions for removal of calcium plaque are often providedwith forwardly shaped rotational drills. Such design presents a risk ofaccidental perforation of the blood vessel walls if such drill is pushedagainst the wall during the procedure. One of the aspects of theinvention provides ways to limit such risks of vessel wall perforationas well as minimizes negative aspects of the procedure on any adjacenttissue.

The prior art is known for drill with the center of mass off center ofthe axis of burr rotation. This creates the centrifugal force whichallows the burr to drill a wider opening in the lumen. However, it alsoleads to potential injuring of the vessel walls. This is becauseoperator cannot control the application of centrifugal force which isconstantly present in prior art devices. Injuring the blood vessel wallsduring atherectomy surgery is one of the leading causes of postatherectomy procedure restenosis—soft tissue growth from the vesselwalls that closes the vessel lumen with soft occlusion.

The present invention offers a solution to prevent unwanted damage tothe vessel walls by creating mechanism allowing an operator to remotelyalter the position of the burr's center of mass as needed for thespecific surgery site requirements.

In prior art, there are known rotational atherectomy systems utilizingdiamond drill tips/burrs to sand hard calcified occlusions to very smallparticles. However, such drills are not suitable or effective inremoving soft occlusions. The present invention offers solutionsallowing use of mechanical drills to safely and effectively cut andremove both hard and soft occlusions in the vessels including in-stentrestenosis ISR growth. The device of the invention is acceptable inorthopedic and other types of body surgery.

SUMMARY OF THE INVENTION

One aspect of the invention provides a device for intrabody surgerywhich includes a cutting arrangement rotatable by a hollow driveshaft,formed by a hollow front cutting region and a rear region. The frontregion is formed by multiple longitudinal drilling sectionsinterconnected by transversely oriented cutting blade sections. Thedrilling sections are positioned at an angle to each other defining incombination with the cutting blades a conically shaped grid formationhaving a hollow internal cavity, with a plurality of ports between thedrilling sections and the blades. A low-pressure zone is developedwithin the hollow internal cavity, wherein cut occlusion materials areaspired by the low-pressure zone through the plurality of ports into thehollow internal cavity for further evacuation from the cuttingarrangement.

Another aspect of the invention provides a surgical device having acutting arrangement for intravascular surgery rotatable by a driveshaft.The cutting arrangement formed by a substantially hollow front cuttingregion and a rear region, a connecting element extending from the rearregion for connection to a distal end of the drive shaft, a sleeve isformed by a wall having a front edge and defining an interior hollowspace. The sleeve is arranged at the connecting element and is movablebetween an expanded and contracted positions. In the contracted positionthe wall of the sleeve is interposed between the cutting region and ablood vessel wall. In the expanded position the front end of the sleeveengages an occlusion and allows the cutting region rotatable by driveshaft to engage with the targeted occlusion through the interior spaceof the sleeve. The sleeve is moved from the locked contracted positionto the expandable position when rotational motion of the driveshaft andthe cutting arrangement are initiated.

A further aspect of the invention provides system for intravascularsurgery. The system comprises a hollow catheter, a cutting arrangementis provided at the proximal end of the catheter, a power sourceenergizing the cutting device, a vacuum source disposed at the distalend of the catheter to create a low pressure zone within the hollowinterior of the catheter and the cutting arrangement. A control unit isprovided to adjust characteristics of the catheter and/or cuttingarrangement based on the inputs obtained from a plurality of sensorsprovided within the cutting arrangement and the catheter. In response tothe signals the control unit adjusts said characteristics depending oncomposition of the occlusion, physical properties of the catheter andcutting arrangement.

As to still another aspect of the invention a plurality of sensors isprovided within the catheter and cutting arrangement to emit and receivevarious signals (optical, electromagnetic, acoustical, capacitancemeasuring) capable of detecting a composition of the occlusion, and toallow the control unit to generate controlling signals controllingoperation of the cutting arrangement.

Yet another aspect of the invention provides catheter assembly incombination with a radiofrequency (RF) electrosurgical instrument. Thecatheter arrangement includes a catheter body having hollow interior. Avacuum source is disposed at a distal end of the catheter to create alow-pressure zone. Multiple active electrodes are disposed a front endof the distal portion of the body for transmitting electrical signalsand produce electrosurgical effects adjacent to the active electrodesfor tissue cutting. Multiple passive electrode is disposed at the frontend of the distal portion in closely spaced relationship relative to theactive electrodes. Each passive electrode includes a passive tissuecontact surface having an area greater than that of an active tissuecontact surface of said corresponding active electrodes, said activeelectrodes. The electrodes are spaced from inner walls of saidsubstantially hollow interior, openings provided to aspirate debris ofablation into and through the hollow interior of the body by thelow-pressure zone.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following drawings, the same parts in the various views areafforded the same reference designators. Referring now to the drawingswhich are provided to illustrate and not to limit the invention,wherein:

FIG. 1A is a diagram illustrating a burr according to one embodiment ofthe invention;

FIG. 1B is a partially sectional diagram of the FIG. 1A;

FIG. 1C is a diagram illustrating an alternate embodiment of the burrshown in FIG. 1A;

FIG. 2 is a diagram illustrating the system of the invention;

FIG. 3 illustrates a distal end of a catheter including a slidablesleeve in an extended position according to another embodiment of theinvention;

FIG. 4 illustrates the slidable sleeve in a retracted position;

FIG. 5 illustrates another embodiment of the slidable sleeve;

FIG. 6 is a diagram illustrating one position of an embodiment combiningthe burr and the slidable sleeve;

FIG. 7 is a diagram illustrating another position of the embodimentshown in FIG. 6 ;

FIG. 8 illustrates another embodiment of the invention;

FIG. 9 is a diagram illustrating an embodiment of the inventionutilizing ultrasound energy;

FIG. 10 is a section view of the embodiment shown in FIG. 9 ;

FIG. 11 is a view of a modified embodiment utilizing the slidablesleeve:

FIG. 12 is a section view of the embodiment shown in FIG. 11 ;

FIGS. 13 and 14 are diagrams illustrating still another embodiment ofthe invention utilizing RF energy;

FIGS. 13A, 14A and 14B are diagrams illustrating a modified embodimentof the invention utilizing RF energy;

FIG. 15 illustrates a modified embodiment shown in FIG. 8 utilizing arotatable blade assembly;

FIGS. 16A, 16B and 61C illustrate an embodiment of the inventionutilizing a stiffening mandrel;

FIG. 17 illustrates an embodiment utilizing a pulling string or wire;and

FIGS. 18A,18B and 18C illustrate surgical tools according to a furtherembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

As used herein in the description of various components, “proximal”refers to a direction toward the system controls and the operator, and“distal” refers to the direction away from the system controls and theoperator and toward a terminal end of the cutter assembly.

In general, the material removal system of the present inventioncomprises a control unit attached to one end of a catheter assembly andan axially translatable, rotatable drive shaft, with a cutter assemblypositioned at the distal end of the drive shaft at least partiallysupported by the guidewire. The material removal system of the inventionfurther comprises multiple sensors positioned at the cutter assemblyarea and along the length of the catheter. In one embodiment the systemincludes wires associated with sensors as well as with delivery ofelectric power to ultrasound or RF emitters.

The cutter assembly is translated over a guidewire to the materialremoval site and is actuated at the material removal site to cut, grindor ablate, or otherwise remove, the occlusive material. The controlunit, and manifold assembly remain outside the body during a materialremoval operation.

We are referring now to FIGS. 1A and 1B illustrating a catheter assembly10 of one embodiment of the invention provided for passing ahigh-rotational-speed burr/cutter 20 into blood vessels as well as toother bodily cavities and adapted to ablate and remove abnormalocclusions and deposits. The burr/cutter 20 actuated by a driveshaft 30and guided through the vessel to the application area by the guidewire50, drills and cuts away the occlusions in the blood vessel.

The flexible guidewire 50 is navigated through one or more lumens suchas blood vessels, to a desired material removal site. The catheterassembly 10 generally houses the burr/cutter 20, drive shaft 30, whichalso defines a lumen 32 which is used among other purposes for theaspiration and/or infusion of fluids. The catheter assembly 10 may befixed to and advanced in concert with the drive shaft 30 to actuate acutter assembly. The guidewire 50 and the catheter assembly 10 areintroduced into a lumen of a patient and navigated or guided to the siteof the desired material removal operation.

A proximal end 33 of the drive shaft is operably connected to vacuum orinfusion pumps, while a distal end 34 of the drive shaft is operablyconnected to cutter/burr 20. Drive shaft 30 is preferably a flexible,hollow, helical, torque-transmitting shaft.

The burr/cutter 20 is formed having teardrop-shaped head 22 with asubstantially hollow front cutting exterior region 28 and asubstantially solid rear region 25. The front region 28 facing theocclusions formed by longitudinal drilling sections 24 extending alonglongitudinal axis of the cutter interconnected by transversely orientedcutting blade sections 36. The drilling sections 24 are positioned at anangle to each other defining in combination with the transverse cuttingblades 36 a conically shaped grid formation culminating at a front tip26 of the head 22. An internal hollow cavity 48 is formed inside of thegrid formation with a central bore 40 passing through the rear region 25and a connecting element 35. The grid formation defines a plurality ofports 46 between the drilling sections 24 and the blades 36. The centralbore 40 and the internal cavity 48 extend longitudinally passing throughthe central part of the burr/cutter body and are adapted to movablyreceive the guidewire 50. The cutter/burr 20 is mounted at the distalend 34 of a flexible drive shaft 30 which transmits torque from atorque-generating device (not shown), such as an electric or pneumaticmotor. The drive shaft 30 is guided by and surrounds a substantialportion of the hollow guidewire 50. It will be discussed in theapplication that ports 46 provide passage of debris from the exterior ofcutter/burr to the central bore 40 and the internal cavity 48.Optionally, ports 46 can be also provided in the rear region 25. Theconnecting element 35 extends from the rear region 25 of the burr in theproximal direction for connection to the distal end 34 of the driveshaft. In one embodiment the connecting element 35 has a cylindricalshape. On the other hand, any conventional configurations of theconnecting element 35 are within the scope of the invention. Asdiscussed later in the application, optionally a stop member 37 (seeFIGS. 6 and 7 ) can be provided at the proximal end of the connectingelement 35.

A plurality of ports 46 connects the exterior surface of the burr withits internal cavity 48 connected to the lumen 32 and providing foraspiration of the debris created from drilling of the hard occlusion orcutting of the soft occlusion material. As illustrated in FIG. 1A, acentral bore 40 passes through the burr/cutter to the internal cavity48. The bore 40 is larger than the outer diameter of the guidewire 50,so that drive shaft 30 with the cutter 20 are slidable and easilytranslatable over guidewire 50. The longitudinal drilling sections 24and cutting blades 36 are formed with sharp edges defining outer cuttingsurfaces. Cutting blades 36 and longitudinal drilling sections 24 mayhave sharpened edges to provide cutting and ablation. The longitudinaldrilling sections 24 and cutting edges are arranged to direct debrisproduced during the cutting operation into the interior of the head 20through the multiple ports 46. Longitudinal drilling sections 24 andcutting blades 36 may, additionally or alternatively, have an abrasiveor cutting material bonded to one or more surfaces of longitudinaldrilling sections 24 Material such as diamond grit is an example ofsuitable abrasive.

In one embodiment of the invention the cutting blades 36 are arranged ina radially symmetrical configuration. In another embodiment the cuttingblades are asymmetrically arranged regarding a longitudinal axis of thehead 22.

In the preferred embodiment ports/openings 46 are formed within thefront region 28 of the cutter/burr, to provide communication with theinternal cavity 48. More specifically, ports 46 provide communicationbetween the cutting front region 28 engaging the occlusion with theinternal cavity 48 and also provide communication with the apertures 54of the guide wire 50 disposed within the cavity 48.

Particles resulted from operation of the burr/cutter 20 are properlyremoved to prevent penetration into a blood stream. Debry particlesresulted from use of the burr/cutter 20 are drawn through the ports 46into internal cavity 48 by low pressure zone created in internal cavityby a vacuum pump connected to the distal end 34 of the drive shaft. Theports 46 also allow debris produced during the operation of the burr 20to be aspired into the ports 54 in the guide wire. It will be discussedin greater detail below that the guide wire 50 made as a hollow tubularstructure is also used as a suction/aspiration conduit for aspiration ofocclusion debris, as the burr/cutter 20 drills away the occlusion. Asdiscussed above, in the alternate embodiment, the ports 46 can be alsoprovided within the rear portion 25 of the burr. The guide wire can beremoved after the burr/cutter 20 is guided within the body lumen to theocclusion. Thus, the entire internal cavity 48 of the burr and the lumen32 of the shaft can be used for aspiration purposes.

The front region 28 of the cuter facing the occlusion may have coatingson its inside or outside for various purposes, for example, forprotection against corrosion by body fluids or for insulation againstthe high energy emitted towards its distal region. It can be of anydimension convenient for its intended use.

Additional structures at the front region 28 may help to preventclogging of the suction conduit. For example, a filter, a screen, amesh, a shield or other barriers can be provided at the distal region ofthe suction conduit.

In an alternate embodiment, as illustrated in FIG. 1C an interior of therear region 25 is substantially hollow. A plurality of knives 29 isprovided at an inner surface of the rear region 25 to further processocclusion materials accumulated within the inner cavity 48. Morespecifically, the knives cut further and transport the materials alongthe chamber to the hollow interior of the drive shaft. In an alternateembodiment a processing unit, similar to the unit 80 illustrated inFIGS. 8 and 15 is formed in the hollow interior of the rear region 25.Such processing unit comprises a chamber having a drive shaft assemblywith a conveying member rotationally positioned thereinside. Theconveying member receives the occlusion material from the inner cavity48, cuts it further and transports the material along the chamber to thehollow interior of the drive shaft.

In one embodiment of the invention the guidewire 50 is formed as ahollow tube. The drive shaft 30 is also hollow. The particle-entrainedblood can flow from the burr 20 through the ports 46 into the interiorcavity 48 and bore 40 and facing the guide wire 50 which is, at leastpartially, disposed within the hollow lumen 32 of the drive shaftconnected to a suction or injection devices.

The hollow tube or central passage 52 of the guide wire 50 is used as aconduit for aspiration of occlusion debris. As illustrated, theguidewire 50 includes a plurality of apertures 54 along its distal end56. Use of such hollow guide wire enables a clinician to catch occlusiondebris more efficiently. This is because, the apertures 54 allow tocatch/collect debris right at the site, where they are produced in thesurgical procedure and before being disbursed. The hollow guidewire 50can be made from metal, or plastic, or grafine or any other materialwhich meets requirement for guide wire and is not permutable for liquidthat contains debris of occlusion or embolus.

The hollow/tubular guidewire 50 if needed, is also capable of deliveringfluid/medication/coolant to a target location. With apertures 54liquid/fluid/medication is allowed to leak from the hollow passage 52out into the vasculature passageway. The location of discharge ofliquid/medication/coolant from the tubular guide wire 50 can becontrolled by controlling size of the apertures 54 as well as thelocation thereof.

Further important functionality of the apertures 54 of the hollowguidewire 50 will become applicable when used in combination with theports 46.

As to the aspiration aspect of the invention, a vacuum pump 70 (see FIG.2 ) creates a low-pressure zone at the proximal end 33 of the driveshaft and the hollow guidewire to aspirate debris of the occlusion orembolus in the blood vessel or body lumen produced by the device of theinvention.

Controllable entry of the cutter/burr 20 into calcifiedocclusions/obstructive lesion has to be assured for its predictableadvancement. Thus, to facilitate such cutter advancement, the driveshaft 30 should be axially translatable with respect to guide wire 50.In the current prior art practice evacuation of residual debris is oftencomplicated and time-consuming technique/procedure. In current practicetools similar to the burr/cutter 20 are nudged into a calcifiedocclusions area during rotation and then retracted. This manipulation inthe prior art procedure permits evacuation of residual debris and toreestablish local circulation before making another cutting cycle on thelesion. On the other hand, in the present invention the ports 46 of theburr/cutter 20 establish a reliable communication between the burrcutting blades 36, the hollow passage 52, and the apertures 54 of theguidewire. In this manner residual debris are evacuated continuouslyduring the procedure without the need for the complicated manipulationsdiscussed above. Further, in the prior art arrangements for catchingocclusion debris are often located behind cutting burrs (either openinginto debris collecting sheath or a debris catching basket). Thisapproach leaves a high probability that some of debris can escape intovasculature of a patient. In present invention the debris are collectedat an immediate area, where the derbies are accumulated due to thenegative pressure suction through the multiple ports 46.

Although the cutter/burr 20 has been discussed above for the removal ofthe occluding material from the blood vessels, it should be noted thatapplication of the burr to many types of the intrabody surgery (asidentified above) also forms a part of the invention. For example, inthe ureteroscopy procedure, which treats and removes stones in thekidneys and ureters, the burr 20 may be used in combination with therespective flexible scope. In the procedure, the doctor passes the scopewith the burr through the patient's bladder and ureter into kidney. Useof the burr 20 may be especially applicable for larger stone removal andcan be combined with other techniques and/or tools includingenergy-based devices to break stones up. Use of the burr 20 may be alsoapplicable in the ureteroscopy for the removal of polyps, tumors orabnormal tissue from a urinary tract. Further application of the burr 20is in percutaneous nephrolithotomy or percutaneous nephrolithotripsy,combined with a small tube to reach the stone, the burr grinds/breaksthe stone up. This action can be combined with the use of high-frequencysound waves, radio frequency or other energy-based devices. After theprocedure the pieces of a stone are vacuumed up and removed from thesystem with a suction arrangement of the invention.

FIG. 1A also illustrates an optional feature of the burr/cutter 20,wherein a center of the mass is not located in the center of the burrrotation, so as to create an orbital effect. More specifically thefeature provides a mechanism 21 that moves the center of the mass awayfrom the center of the burr rotation providing an operator with anothercontrolling function. Thus, the center of mass is moved away from centerof the burr rotation when operator wishes to drill a wider opening inthe occlusion. On the other hand, the center of mass of the burr remainsin the rotational center during other periods of surgery, thuspreventing injuring to the blood vessel walls by the uncontrollablerotational forces that press the burr ablative surfaces to the vesselwalls. As illustrated in FIG. 1A, the mechanism 23 consists of multipleor at least two weights initially located symmetrically relatively tothe axis of the burr rotation, with one of the weights 23 being movedaway from the rotational center. A pivoting arm 31 with the weight 23pivots away from the connecting portion 35 when it is released by theoperator. In the mechanism release and movement of the arm can becontrolled in any conventional manner, mechanically, electrically,wirelessly, etc.

We are referring now to FIGS. 18A, 18B and 18C illustrating furtherembodiments the burr/cutter of the invention provided for use inorthopedic and other types of surgery. Application of these surgicaltools includes, but is not limited to drilling of the bones and surfaceablation, scrubbing or scraping of bones, ligaments, meniscus, cartilageetc. The bur/cutter 20′ of FIG. 18A is formed having conical head 22′with a substantially hollow front cutting exterior region 28′ and asubstantially solid rear region 25′. The front region 28′ facingoperation site is formed by longitudinal drilling sections 24′ extendingalong longitudinal axis of the cutter interconnected by transverselyoriented cutting blade sections 36. The drilling sections 24′ arepositioned at an angle to each other defining in combination with thetransverse cutting blades 36 a conically shaped grid formationculminating at a front tip 26′ of the head. The grid formation defines aplurality of ports 46′ between the drilling sections 24′ and the blades36′. The ports 46′ provide passage of debris from the exterior ofcutter/burr to the internal cavity 48′. As discussed above, conicallyshaped surfaces of the burr/cutter 20′ are used for drilling, surfaceablation of the bones, etc. The bur/cutter 20′ of FIG. 18C is similar tothat of FIG. 18A, but is also provided with an exterior shield/cover 45″preventing the materials/particles developed during the surgery frombeing dispersed, so as to be directed into the interior cavity 48′ forevacuation from the device by suction. The bur/cutter 20″ of FIG. 18B isformed having cylindrically-shaped head 22″ with a substantially hollowfront cutting exterior region 28″ and a substantially solid rear region25″. The front region 28″ is formed by substantial straight drillingsections 24″ interconnected by transversely oriented cutting bladesections 36″. The drilling sections 24″ define in combination with thetransverse cutting blades 36″ a cylindrically shaped grid formation witha plurality of ports 46″. Optionally, a plurality of knifes 29″ can beprovided at an inner surface of a hollow rear region 25″ to furtherprocess occlusion materials accumulated within the inner cavity 48″.

As illustrated in FIG. 2 the control unit 12 houses a programmable logiccontroller 14 or microchip and power source 15 in operable communicationto provide power and to control operation of various units of the systemof the invention. The control unit 12 preferably comprises a basearranged so that the control unit may be stably supported on a worksurface or a body surface during material removal operations. Thecontrol unit 12 also preferably incorporates control systems foractuating, adjusting and providing system information concerning power,drive shaft rpm, drive shaft axial translation, aspiration, infusion,which displays reading of sensors located on the catheter and cuttinginstrument and the like. The control unit may include, but not limitedto vacuum control unit, cutter advancer unit, guidewire control unit,cutter assembly drive control, and aspiration and infusion control unit.The control unit 12 also controls a block providing informationconcerning operating conditions and feedback from the material removalsite to the operator. By means of a computer or microchip 14 the controlunit 12 utilizes inputs received from multiple sensors 16 located at theburr/cutter 20 and/or other critical regions of the catheter assembly tocontinuously updated output to an operator including such operatingparameters as temperature at the material removal site; cutter assemblyrotation rate and/or advance rate; aspiration rate and/or volume;infusion rate and/or volume; and the like. Control unit 12 mayadditionally provide adjustable controls permitting the operator tocontrol operating parameters of the cutter assembly and material removaloperation.

As illustrated in FIG. 2 , the control unit 12 is provided to regulatethe power source 15 for the optimum output level based on type andcharacteristics of the targeted occlusion (hard, soft, blood, etc.)and/or characteristics of the burr catheter (length, diameter,temperature, etc.). Characteristics of the control unit 12 may beadjusted by the operator or automatically based on inputs from thesensors 16. Controlling various characteristics/parameters at theoperation cite are based on the information provided by sensorspositioned at the distal end of the catheter and the burr, such as forexample speed of rotation, temperature, etc. Such characteristics can bemanually or automatically adjusted based on the signals and datareceived from the sensors 16 installed within the cutter/burr 20.

Sensors 16 may emit and receive various types of signals (optical,electromagnetic, acoustical, capacitance measuring) that will changeparameters depending on the composition or other physical properties ofthe occlusion and/or tissue surrounding occlusion and/or physicalcharacteristics of the catheter itself, so as to allow the control unit12 to calculate and generate proper signals controlling operation/speedof rotation, etc. of the burr 20.

Sensors 16 located at the front portion 24 of the burr 20 are able torecognize (determine) the physical and chemical properties of theocclusion. A computer or microchip 14 associated with the control unit12 receives and analyzes information/data obtained by the sensors 16 andgenerates signals to adjust parameters of the power source 15 tooptimize the destruction of an occlusion in the blood vessel and/or toproduce other desired effect on targeted tissue. As an example, thecontrol unit 12 analyzes information/data obtained by the sensors 16 andgenerates signals to adjust parameters of the power source 15 tooptimize rotational speed, etc. of the burr 20. This includes alsoapplying different physical mechanisms of action to destroy occlusion.For example, the cutting arrangement can combine mechanical cutting tooland RF cutting electrodes which can be activated by the control unit 12interchangeably based on the signal from the sensors describing theocclusion material characteristics which may require different tools forbest removal.

The sensors 16 are capable of detecting the level ofhardiness/calcification, water/moisture content, etc., within thematerial of an occlusion. As the burr 20 passes through various areas ofthe occlusion, optimal levels of rotational speed, etc. can be achievedfor each zone of treatment. For example, a higher speed of rotation canbe provided for the destruction of calcinated occlusion having higherdegree of hardiness. On the other hand, lower speed will be generatedfor the areas with softer occlusion materials for more effective bladecutting action.

Utilization of the cutting burr 20 is also accompanied by automatictarget feedback, thermal feedback for example, to precisely control thespeed of rotation, etc. This is needed to prevent damage to surroundingtissue. For this purpose, non-contact thermal detectors 17 can beprovided. The output of the non-contact, thermal detectors 17 can beused to adjust the output of the power source 15 to maintain selectedcharacteristics including temperature at the treatment site.

In the invention to effectively control the destruction of theocclusion, a condition of the entire artery body and/or the tissuesurrounding the operation site is monitored by the detector 17 adoptedto detect irradiation reflected from such tissue. One of the essentialfunctions of the detector 17 is to control the effect of thedrilling/ablation on the tissue surrounding the site. In everyindividual case a doctor sets specific rotational, etc. characteristicsto produce the required effect. If a situation at the operation sitebecomes unfavorable, for example the temperature exceeds predeterminedlimits, the detector 17 generates a signal directed to the control unit80, which in turn produces a correcting signal to the power source 15 orto the control unit 12.

The computer or microchip 14 of the control unit 12 receives andanalyzes the information obtained by the detector 17 and to generate acontrol signal to adjust parameters of the power source 15 in such a wayas to optimize the destruction of an occlusion in the blood vessel orother desired effect on targeted soft tissue.

In an alternate embodiment the control signal generated by the thermaldetector 17 energizes the cooling arrangement (see above) to directly orindirectly lower/adjust temperature at the site. This is necessary toexclude possibility of damaging an adjacent tissue. The detector 17 andthe sensors 16 can be made utilizing a wide variety of photoelements,photoresistors, photodiodes and similar devices. Overheating may alsooccur in the length of the catheter particularly where the catheter isbended to sharp angle thus installing temperature sensors along thelength of the catheter may improve safety profile of the device.

As discussed above, frictional forces resulted from theengagement/drilling between the burr 20 and the material of theocclusion, as well as other factors may result in temperature elevationof the surrounding tissue. In the invention, the temperature elevationoccurs controllably without causing irreversible thermal damage to thesurrounding tissue of the arteries. The control unit 12 adjusts theenergy to maintain a pre-selected target temperature at the site. In oneembodiment of the invention, to maximize patient safety, an optionalcontinuous or pulsed cooling device can be provided to deliver a coolantfrom the infusion material storage 55 by means of the infusion pump 53through the hollow guide wire 50 to the operation site during or aftersurgical procedure.

The diagram of FIG. 2 schematically depicts a system according to oneembodiment of the present invention that may be connected to the cutter20 to evacuate the ablated or cored bodily material from a subject'svascular system using various embodiments of the cutter/burr 20. Thevacuum pump 70 provided at the proximal end 33 of the drive shaftcreates low-pressure zone resulted in suction pressure within the lumenor hollow inner space 32 of the drive shaft and the passage 52 of theguide wire 50 to evacuate cut and/or ablated bodily material directlyfrom the operating site in the vascular system.

In another embodiment, the vacuum pump 70 is interconnected to a pulsemodulator 71, the actuation of which creates one or more pressuredifferentials to the aspiration system. Accordingly, by the use of thepulse modulator 71, rather than creating a constant suction pressurewithin the system to evacuate cut and/or ablated bodily material from asubject's vascular system, the aspiration system of the inventionapplies alternative pressure(s), thereby creating pulses of suctionpressure within the lumen. Utilizing a series of constant and/or varyingpressure pulses is potentially beneficial in aspirating bodily material,particularly when aspirating larger cylindrically looking core or pluglike shapes of bodily material.

Aspirated liquid and/or particle from an area near distal end of thetool are accumulated and stored in the disposable debris storage 76. Afilter 74 can be also provided upstream of system for filtering debrisand aspirated bodily material and also for providing visual feedback toa user related to the type, quantity, and flow rate of material beingremoved from a patient. The debris container 76 may be in fluidcommunications with the vacuum pump 70 and may include one or more knowndevices for collecting and filtering materials removed from a patient.The container 76 may have transparent sidewalls for providing visualfeedback to a user regarding flow-rate, content, coloration, etc. Thoseof skill in the art will appreciate that various types of collectioncontainers may be used. The collection container 76 and/or filter 74 mayalso comprise one or more custom filter features with various meshsizes, capacities, etc. based on the specific application.

The distal end 56 of the hollow guide wire 50 functioning as a suctionconduit can be made of a variety of flexible or rigid materials or acombination of both, such as metal or plastics. Still further, thedistal end 56 of the guide wire formed as a suction conduit can be madeof a material different from the body of the hollow guidewire. Forexample, one might want to make the distal end 56 with a moreheat-resistant material to withstand high energy directed to it. It mayalso be desirable to use a more impact-resistant material to withstandthe initial impact from the solid particles drawn by the suction force.

Referring now to FIG. 3 , showing an expanded/working position of asleeve 60 provided for slidable motion along an exterior of the catheteraccording to another embodiment of the invention. The distal end of thecatheter assembly 10 is provided with the sliding sleeve 60 having anactivating mechanism 62 provided for controllable movement of the sleeveback and forth along the catheter exterior. In one embodiment of theinvention the activating mechanism 62 is spring controlled. However, theactivating mechanism 62 can be energized/actuated in any conventionalmanner, such as for example electrical, pneumatic, etc. mechanisms arecontemplated. The front/distal end 65 of the sleeve 60 is designed toestablish a tight contact with the occlusion. For example, the distalend 65 can be made of a resilient material capable of adopting toevolving configuration of the external part of the occlusion during theprocedure. Therefore, catching the occlusion debris and channeling theminto the hollow tubular passage 66 for aspiration has been enhanced. Asillustrated, in the working position the sleeve 60 extends outwardlyfrom the exterior of the catheter 10. In this arrangement the diameterof the outer periphery at the distal end of the catheter is slightlyincreased. In the contracted position sleeve 60 is positioned along theexterior surface of the catheter.

In another embodiment, illustrated in FIG. 4 , a circumferential recess68 is formed within the distal end of the catheter body having the depthand length corresponding to the respective dimensions of the sleeve 60.The exterior surface of the sleeve is in flash with the exterior surfaceof the catheter. Prior to the catheter's placement through the bloodvessel lumen to the operation site, the sleeve 60 is pressed inwardly inthe direction of the proximal end to overcome resistance of theactivating mechanism 62. As a result, the sleeve 60 is submerged withinthe circumferential recess 68. In this locked position the exterior ofthe sleeve 60 is in flash with the exterior of the catheter. Upondelivery and proper positioning at the site, the activating mechanism 62is released-unlocked and the sleeve 60 is moved to the expanded workingposition to provide a tighter contact between the distal end 65 of thesleeve 60 and the occlusion.

Turning now to FIG. 5 showing an alternate embodiment, provides tofurther increase ability of the sleeve to accommodate randomly shapedocclusion for optimally sealing the cutting/drilling site. Asillustrated in FIG. 5 , longitudinal slits 67 are circumferentiallyarranged within the sleeve body forming a plurality of segments. Theslits 67 extend inwardly from the distal end of the sleeve to separatethe sleeve body into a plurality of segments 69. In one embodiment ofthe invention, the front area of the segments 69 can be curved and/orformed from a resilient material to further improve engagement with theocclusion. Any reasonable number and configuration of the slits and/orsegments are within the scope of the invention.

Turning now to FIGS. 11 and 12 showing another embodiment of a sleeveassembly 120 provided to further increase ability of the sleeve toaugment randomly shaped occlusion for optimally sealing thecutting/drilling site to maximize catching debris of the destroyedocclusion. Longitudinal slits are circumferentially arranged within thesleeve body forming a plurality of segments. Such segments are able tolongitudinally move independently each other to optimally adapt to therandom shapes of possible occlusion deposits. The assembly 120 consistsof an external base 122 formed by a cylindrical side wall 131 and a rearwall 124, so that a hollow inner cavity 129 is defined therebetween. Aplurality of separated from each other engaging segments 127 arepositioned in the inner cavity 129 for independent slidable movementalong a longitudinal axis the assembly. Any reasonable number of thesegments can be symmetrically arranged within the cavity. Each engagingsegment consists of at least a front part 126 adapted for engagementwith an occlusion and a rear part 128 adapted for movement within theinner cavity 129. A biasing member or a spring 130 is positioned betweenthe rear part 128 of each segment and the rear wall 124 of the base. Inuse, upon the sleeve approaching the occlusion, the front parts of eachsegment which is pressed by the biasing member 130, engages therespective area of the occlusion having a specific configuration. Thisoccurs independently from other segments. The front part 126 of eachsegment is formed to provide a tight contact with a respective area ofthe occlusion. In one embodiment, the front part 126 is made of aresilient material capable of adapting to evolving configuration of therespective part of the occlusion. Therefore, the sleeve assembly 120provides an improved tighter contact between the front parts of thesegments and the occlusion during the procedure.

FIGS. 6 and 7 illustrate yet another embodiment of the invention whichcombines application of the above-discussed burr/cutter 20 with thesliding sleeve 60 movably positioned at the connecting element 35 of theburr. The stop member 37 is provided at the proximal end of theconnecting element 35. As illustrated, the sleeve 60 is arranged for amovement along the connecting element 35. The advancement of the sleevein the proximal direction is limited by the stop 37. The hollow interiorof the sleeve defines an interior space 64 which accommodates the burr20 and serves as its housing. As illustrated in FIG. 6 , in the initialposition on the connecting element the burr 20 is positioned within thechamber 64, so that the wall of the sleeve extends over the burrexterior. This position of the sleeve is locked by a key 39. Thisarrangement allows for safe travel of the burr 20 covered by the sleeve60 through a blood vessel to an occlusion area. When the burr covered bythe sleeve reaches the occlusion, rotation of the burr by drive shaft isinitiated. The torque moment at the beginning of the rotation breaks thekey 39 causing disengagement of the burr and sleeve. Thus, independentoperation of the bur and the sleeve is initiated. As illustrated in FIG.7 rotating burr 20 drills the occlusion. On the other hand, the sleevebecomes independently slidable by means of the loaded spring arrangement41 which pushes the sleeve 60 toward the occlusion to establish acontact therebetween, so as to further maximize catching of the cutdebris into the internal hollow space 48 of the burr.

An abrasive or cutting material is bonded or by any other conventionalmeans attached to the distal end 67 of the sleeve, forming an auxiliarycutting region. IN an alternate embodiment, a cutting element or acutting edge can be formed at the distal end 67 instead of the abrasivematerial. In this manner this assembly is provided with two cuttingregions, including the burr/cutter 20 and the auxiliary cutting regionat the distal end 67.

To drill away the occlusion the rotating burr 20 is moved by theadvancing catheter in the distal direction. After that rotation motionof the sleeve 60 is initiated. In this process a major central portionof the occlusion is cut or drilled away by the cutting burr 20.Furthermore, as illustrated in FIG. 7 , a portion of the occlusion alonginner walls of the blood vessel or lumen is removed or cut away byrotation of the auxiliary cutting region provided at the distal end 67of the rotating sleeve. Thus, this arrangement enables a practitioner toeliminate or cut away the entire occlusion in one procedural step. Inthe prior art however, the portion of the occlusion disposed along theinner walls of the blood vessel or lumen is not removed due torelatively small outer diameter of the burr.

During the process of inserting the catheter through the blood vesselsto the point of occlusion and during the cutting procedure, walls of thesleeve 60 isolate the burr 20 from the blood vessel walls 63. Thus, therisk of accidental perforation of the blood vessel walls 63 or any otheradjacent tissue during the procedure is minimized. The interior space 64of the sleeve creates a conduit which accommodates materials cut duringthe procedure and improves the flow of various fluids during aspirationand/or infusion.

Among essential functions of the sleeve assembly illustrated in FIGS. 6and 7 is to form an enhanced engagement with the occlusion. Thus, thatthe distal end of the sleeve provides, upon engagement with occlusion anisolation of and a potential vacuum within the space 64, having the burr20 being positioned thereinside. Upon rotational/drilling motion of theburr, created derbies or cut materials are accumulated/disposed withinthe inner space 64 and evacuated by suction through the plurality ofports 46 into the internal hollow space 48 of the burr. The inventionalso provides the burr—sleeve assembly of various sizes, so as to enablea practitioner to more precisely accommodate specifics or sizes of eachvessel or lumen being operated upon. Thus, the larger size isaccommodated by the sleeve 60 having a larger diameter, whereas smallerdiameter sleeves are provided for smaller size vessels. This feature isespecially important when a close contact between the exterior of thesleeve and interior of the vessel is needed for the removal of parts ofthe occlusion disposed adjacently to the vessel's interior surfaces.During the stage of inserting the catheter into the vessel and throughits movement through vascularity to the surgery site (occlusion) thesleeve 60 is locked in such a way that it surrounds the burr/cuttingsurfaces thus protecting the internal walls of the blood vessels frombeing injured by the burr cutting surfaces and therefore minimizing riskof in vessel unwanted growth of soft tissue as a reaction to the woundscaused by such cutting surfaces being pushed through the vessels to theocclusion site. When burr/cutting arrangement reaches the occlusion sitethe sleeve 60 is released from the locked position with start of theshaft rotation.

It should be noted that application of the slidable sleeve 60 is notlimited to the removal of the occluding material from the blood vessels.The sleeve 60 can be used in many types of the intrabody surgery (asidentified above). For example, it can be used in ureteroscopyprocedure, which treats and removes stones in the kidneys and ureters.The sleeve 60 may be used in combination with the flexible scope, whichis passed through patient bladder and ureter to provide an enhancedcontact with kidney. Use of the sleeve 60 facilitates larger stoneremoval, combined with RF cutting device, which passes through the scopeto break stones up. Another example is use of the movable sleeve 60 inthe ureteroscopy for the removal of polyps, tumors or abnormal tissuefrom a urinary tract in orthopedic or general surgery. Similar to theabove discussed applications, the sleeve 60 can be used in percutaneousnephrolithotomy or percutaneous nephrolithotripsy, combined with a smalltube to reach the stone and break stone up with high-frequency soundwaves or RF cutting device. The broken pieces are vacuumed up andremoved from the system by a suction arrangement of the invention.

Although the assembly combining the burr/cutter 20 with the slidingsleeve 60 has been discussed above, it should be noted that use of thecutter/burr with other type of protective devices is within the scope ofthe invention. For example, an assembly where the burr/cutter 20 iscombined with the sleeve arrangement illustrated in FIGS. 11,12 and 14is also contemplated.

In a further embodiment of the invention illustrated in FIG. 8 , aprocessing unit 80 with a rotatable blade assembly or cutting element 85is provided at the distal end of the drive shaft 30 to cut and maceratethe occlusion (embolus) and to evacuate cut materials away from thesite. The rotatable blade assembly 85 includes a hub and a plurality ofblades arranged at the hub. Each blade is formed having a leadingcutting edge and a trailing edge and extend in a plane generallyperpendicular to the axis of rotation.

The processing unit 80 comprises a chamber 82 having a drive shaftassembly 84 with a conveying member 86 rotationally positionedthereinside. The conveying member 86 receives the occlusion material cutby the cutting element 85 and transports the material along the chamber82.

The drive shaft assembly 84 both transports cut tissue/material withinthe processing unit 80 and drives rotation of the cutting element 85. Inother embodiments the drive shaft 84 may transport the cut tissueproximally within the processing unit 80 but may not drive rotation of acutting element 85. FIG. 8 shows that the drive shaft assembly 84 isattached to the cutting element 85.

The drive shaft 84 is generally cylindrical and may comprise a solidtube or a hollow tube. The drive shaft with the conveying member 86 ismanufactured to be flexible enough to facilitate navigation throughtortuous vessel anatomy and strong enough to withstand the stressesencountered by high speed rotation, transmission of torque through thedriveshaft to the cutter 85 at the distal tip of the processing unit 80,and transport occlusion material. The conveying member 86 may be aseparate element which is attached or affixed in some manner to asubstantially cylindrical drive shaft. Alternatively, the drive shaft 84and the conveying member 86 may be formed as a single unitary element.

The drive shaft 84 is formed having a central lumen 88, which is used todeliver the guidewire 50, and may be coated with a lubricious materialto avoid undesirable binding with the guidewire. The central lumen 88 ofthe shaft 84 may also be used to deliver fluids to the operative sitesimultaneously with or in place of the guidewire.

In one embodiment of the invention a plate 95 having a plurality ofholes 97 passing from one face of the plate to the other is positionedwithin the chamber 82 transversely to the longitudinal axis thereof. Inthis manner, the occlusion material initially cut by the cutting member85 is delivered by the conveying member 86 to the chamber 82 for furtherprocessing by passing through the plurality of holes 97 of the plate 95.The receiving chamber 82 along with the shaft 84 with the conveyingmember 86, and the optional plate 97 forms a first processing section 83of the unit 80. Optionally it can be a second chamber 82′. Occlusionmaterial from chambers 82/82′ is pushed by the conveying member 86 tothen space 52 through which the debris are vacuumed into the disposablestorage located in the control unit.

The conveying member 86 may be an auger type system or anArchimedes-type screw that conveys the debris and cut material generatedduring the procedure away from the operative site. The conveying member86 has raised surfaces or blades that drive materials away from theoperative site. Blades of the conveying member 86 may extend up to afull diameter of the internal chamber 82 or a part of it.

Debris can be evacuated outside the body by the conveying member 86action along the length of the catheter and with or without supplementof the vacuum pump connected to the catheter. Alternatively, the debrismay be accumulated in a reservoir within the device.

Optionally, a plurality of generally equally spaced ridges 87, which canbe collapsible in nature, are provided, extending from an inner wall 89of the chamber. The ridges 87 tend to provide sufficient clearance aboutthe conveying member 86. In this manner, initially processed occlusionmaterials can be propelled through the processing unit 80 withoutdevelopment of back pressure due to clogging in the assembly. The ridges87 are aligned to increase material throughput rate by channelingmaterial towards the proximal end of the unit 80.

As further illustrated in FIG. 8 , optionally the tool of the inventioncan be provided with a second processing section 90. The second section90 comprises a second chamber 82′ with a second drive shaft 84′ sectionhaving a conveying member 86′ with a second pitch generally somewhatsmaller than the pitch of the first conveying member 86. The first andsecond conveying members are co-axially arranged and formed with alongitudinally extending apertures used to accommodate, among otherfunctions the hollow guidewire of the invention. The second section 90can be optionally provided with a second plate 95′ having a secondplurality of holes 9T passing therethrough from one face thereof to theother. The holes 97′ of the second plate 95′ may be smaller than theholes of the first plurality of holes 97. In this manner, as previouslydiscussed, the occlusion materials are initially processed by passagethrough the first plurality of holes 97 under the impetus of the firstconveying member 86. Then, such initially processed material is furtherprocessed to a smaller size by passage through the second plurality ofholes 97′ under the impetus of the second conveying member 86′. Thefirst and second conveying members can be formed as one unitarycontinuous structure or as two independent units. The debris are pushedby conveying member 86′ through the opening 97′ into space 52 connectedwith the vacuum in the control unit.

The second processing chamber can be employed in certain situations, forexample, where highly calcified occlusion is encountered. In thisinstance, the material exiting the first plurality of holes can be inthe form of relatively coarse agglomerations. Such material is thenpicked up and propelled by the second conveying member, so as to help toguide the material towards the second plate. As the cut material passesthrough the second plurality of holes of the second plate, furtherreduction of sizes of the occlusion particles takes place.

As illustrated in FIG. 8 the processing unit 80 can be optionallyprovided with the sleeve 60 slidably arranged at the exterior part ofthe catheter. In the illustrated expanded position, the sleeve 60extends outwardly from the distal end of the unit 80. The hollowinterior of the sleeve forms an interior space 64 that serves as ahousing for the cutting element 85. An area of connection between thedrive shaft and the cutting element 85 is also accommodated in the space64. When the sleeve 60 is retracted in the proximal direction, thecutting element 85 is exposed.

In use when the sleeve 60 is in the expanded working position, thedistal end 65 of the sleeve 60 engages the occlusion, then the cuttingelement 85 by the drive shaft is delivered through the interior space 64to the operation site. The interior space 64 also creates a conduitwhich accommodates materials cut during the procedure and to improve theflow of various fluids during aspiration and/or infusion. In thisembodiment the cutting element 85 is precisely delivered to theocclusion. Further, the walls of the sleeve 60 isolate the cuttingelement 85 from inner surfaces of the blood vessel walls to minimize therisk of accidental perforation/damage of the blood vessel walls.

In operation of the processing unit 80, initially the occlusion materialcut by the cutting element 85 is processed and fed into the chamber 82.In the embodiment where the plate 95 is provided, the drive shaftassembly 84 having a conveying member 86 propels the cut occlusionmaterial towards and through the holes 97. Thus, size of the initiallycut occlusion materials is reduced to become more adaptable for suction,collection and disposal as previously discussed. To further reduce sizeof the cut occlusion materials, the second processing chamber 82′ nay beutilized in the above-discussed manner.

Application of the processing unit 80 combined with the cutting element85 to many types of the intrabody surgery (as identified above) alsoforms a part of the invention. For example, in ureteroscopy procedure,which treats and removes stones in the kidneys and ureters, theprocessing unit 80 may be used in combination with the respectiveflexible scope. Use of the processing unit 80 is also applicable forlarger stone removal, combined with RF cutting device, which passesthrough the scope to break stones up. Further, in the ureteroscopy theprocessing unit 80 can be used for the removal of polyps, tumors orabnormal tissue from a urinary tract. The processing unit 80 includingthe cutting element 85 is also usable in percutaneous nephrolithotomy orpercutaneous nephrolithotripsy, combined with a small tube to reach thestone and break stone up with high-frequency sound waves or RF cuttingdevice. Further, the processing unit 80 can be used in intrabody,laparoscopic and endoscopic orthopedic surgeries including but notlimited to spine surgery, knee or hip replacement and similar. Theprocessing unit 80 can be used for safe and effective removal of anysoft tissue. After the procedure the pieces are vacuumed up with asuction arrangement of the invention.

Turning now to FIG. 15 showing a processing unit 180 provided with acutting assembly 185 at the distal end of the drive shaft 184. Theassembly 185 is formed with a hub 160, a plurality of blades 162arranged at an outer band 164 arranged at outer peripheries of theblades 162. In one embodiment, the hub, the blades and the outer bandcan be integrally formed. Each blade 162 is formed having a leadingcutting edge 168 and a trailing edge 167, which extend in a planegenerally perpendicular to axis of rotation. The outer band 164 has afront/distal area 166 facing the occlusion and a rear/proximal area. Anabrasive cutting material is bonded or by any other conventional meansattached to the distal area, forming an auxiliary cutting region 170. Inthe alternative, a cutting element or edge can be formed at the frontarea 166 of the outer band. Thus, the cutting assembly 185 is formedwith two cutting regions, including the primary cutting region defied bythe leading cutting edges 168 of the blades 162 and the auxiliarycutting region 170 defined the front area 166 of the outer band. In use,upon approaching the occlusion, the leading edges 168 of the primarycutting region remove or cut away a central area of the occlusion. Onthe other hand, tissues of the occlusion at the inner walls of the bloodvessel are eliminated or cut away by the auxiliary cutting region 170.In the prior art procedures due to smaller outside diameter of thecutting tools relative to the inner diameter of the blood vessels andother reasons, such occlusion tissue often remains unremoved. Thus,application of the cutting assembly 185 of this embodiment enables apractitioner to eliminate or cut away the entire occlusion in oneprocedural step. This embodiment can be used for cutting soft occlusionstissues and is particularly applicable in stent restenosis procedures.

Similar to FIG. 8 , the embodiment of FIG. 15 the processing unlit 180includes a chamber 182 with the drive shaft 184 provided with theconveying member 186. The drive shaft and the conveying member transportremoved or cut tissue in the processing unit 180 and drive rotation ofthe cutting assembly 185. As illustrated in FIG. 15 , the catheter isformed with an exterior sheath/to be shown/spaced from an inner hollowtube receiving the drive shaft. The drive shaft 184 is formed having thecentral lumen 188 used to deliver the guidewire 50 and may be also beused to deliver fluids to the operative site. To facilitate rotation ofthe drive shaft and the cutting assembly 185, the distal end/to beshown/of the processing unit 180 is separated from the cutting assembly185 by a gap/to be shown/. Also, as illustrated in FIG. 15 , the distalend can be flared. Furthermore, a lubricant can be delivered through thespace separating the interior of the hollow tube and the drive shaft.The walls of the housing 180 may optionally expand to a higher diametercomparing with the average diameter of the catheter to accommodate awider blade assembly 185 to optimally ablate occlusions in a largerdiameter vessels.

The occlusion material cut by the cutting assembly 185 is delivered bythe conveying member 186 to the chamber 182 for further processing, aspreviously discussed in the embodiment of FIG. 8 . Then debris ofprocessed cut material are evacuated through the space separating theexterior sheath from the inner tube with or without supplement of thevacuum pump connected to the catheter. Alternatively, the debris may beaccumulated in a reservoir within the device.

Turning now to FIG. 9 illustrating still another embodiment of theinvention, wherein a source (generator) of ultrasound energy is disposedat the proximal end of the catheter. In the illustrated embodiment thesource is in the form of a pair of spaced from each other ultrasoundwaive generators provided to generate ultrasound waves/beams focused ona specific area in the vicinity of the proximal end of the catheter. Inuse the proximal end is delivered to the occlusion, so that theultrasound beams are focused to an area within the body of the occlusionfor selective destruction of the occlusion tissue. Since the focus isspaced from the surrounding tissue, the risk of collateral damage to thesurrounding blood vessels walls is minimized. Although a pair ofcooperating ultrasound generators is shown, it should be appreciatedhowever that the distal end of the catheter can be provided with anyreasonable number of cooperating ultrasound generators.

As illustrated in FIG. 9 , a distal end 102 of the catheter 100 isformed having a convex-shaped region 104 with one pair of thesymmetrically arranged ultrasound energy generators 106 and 108. Theconvex-shaped region 104 reflects the energy emitted from the ultrasoundgenerators and the beams 110 of the ultrasound energy are optimallyfocused at a specific/predetermined area within the body of theocclusion for a selective destruction of tissue. The focus of the beams110 is disposed along the longitudinal axis A-A of the catheter andspaced from the distal end 102.

Optionally the distal end 102 of the catheter is made from a resilientmaterial and the convex-shaped region 104 forms a suction cup, tofurther improve engagement between the distal end and the occlusion.This arrangement prevents spreading and facilitates catching of thedebris. In addition, ultrasound energy detectors and/or other sensors105, including but not limited to the temperature sensor, can beprovided at the distal end 102 to control operation of ultrasound energygenerators 106 and 108. The sensors/detectors 105 detect data relatedphysical properties and chemical composition of the occlusion andtransmit such data to the control unit. As previously discussedregarding FIG. 2 , the computer or microchip 35 of the control unit 30receives and analyzes the information obtained by the sensors/detectors105 and generates a control signal to adjust functionality of theultrasound energy generators 106 and 108, to optimize the destruction ofan occlusion and produce other desired effects on targeted soft tissue.

As illustrated in FIG. 10 the convex-shaped region 104 provided with theultrasound energy generators 106, 108 can be used with the sleeve 60slidably arranged at the exterior area of the catheter 114. In theillustrated expanded position, the hollow interior space 64 of thesleeve 60 serves as a housing for the convex-shaped region 104 includingthe ultrasound energy generators 106 and 108. In use the sleeve 60 isplaced into the expanded, working position, and the distal end of thecatheter with the ultrasound energy generators are delivered through theinterior space 64 to the close proximity of the occlusion. In thismanner, the ultrasound beams 110 are optimally focused at a specificarea at the body of the occlusion for a selective destruction of thetissue. The interior space 64 of the sleeve 60 forms a conduit whichaccommodates materials cut during the procedure and improves the flow ofvarious fluids during aspiration and/or infusion associated with use ofthe catheter. The convex-shaped region 104 with the ultrasound energygenerators 106,108 are precisely delivered to the occlusion, and thewalls of the sleeve further isolate the generators 106,108 from innersurfaces of the blood vessel walls 112, minimizing the risk of theiraccidental damage and/or perforation.

Turning now to FIGS. 13 and 14 illustrating electro-surgical tool 190according to a further embodiment of the invention. In this embodimentof the invention electro-surgical effects of ablation and resection areaccomplished by applying a radio frequency (RF)current to the tissuethrough active electrodes (+)192, from which the RF current flows to aground or return (−) electrodes 194. As it passes through tissue fromthe active electrodes to the ground electrodes, the RF current cutsand/or coagulates the tissue, depending on power and wave lengthcombinations. A flexible elongated hollow tubular body 200 is usuallyflexible and constructed of an electrically insulative material. Any ofa number of polymeric or plastic materials may be employed for thispurpose. The distal end 197 of the tool includes a plurality of theactive electrodes and associated ground electrodes. A source (generator)of RF (radio frequency) energy (not shown) is disposed at the proximalend 198 of the tool or proximal end of the catheter in the controlunit—power source. As illustrated in FIG. 13 , in one application thecatheter includes multiple electric wire conductors 191 longitudinallyextending within a hollow interior of the body 200 to deliver electriccurrent/voltage to the RF electrodes 192, 194 provided at the distalend.

The ground electrodes (−) 194 are positioned close enough to the active(+) electrodes 192, so that the RF current flows a short distance. Inthis manner, loss of RF current by dissipation to the tissue and/orconductive irrigation fluids is reduced, and the desired effect orcutting performance of the tool 190 is not significantly degraded. Inthe bipolar instruments of the invention, the active electrodes 192 andthe associated return electrodes 194 are disposed in close proximity toone another. So that there is less likelihood of current flow to tissuesother than intended tissue being operated upon. Well-controlled bipolarRF energy delivery of the apparatus of this embodiment is preferred whenablating thinner or more delicate areas of tissue or when there isconcern of possible collateral damage to target or non-target tissue.

As shown in FIG. 13 , the wire conductors 191 which deliver RF currentto the electrodes are located within the interior cavity of the tubularbody. The wire conductors and electrodes are designed so that they donot take up significant amount of the interior volume of the tubularbody 200 and that the individual electrodes/wires do not interfere witheach other. Open spaces formed within the catheter body between thewires and/or electrodes are used to evacuate ablated bodily materialproduced during the procedure. The evacuation can be accomplished, forexample by a vacuum pump provided at the proximal end of the systemcreating allow-pressure zone resulted in suction pressure within thehollow inner space of the catheter, so that ablated bodily materialdirectly removed from the operating site.

In an alternate embodiment, as illustrated in FIG. 13A electro-surgicaltool 190 may also be constructed as a bipolar RF device with a singlereturn/passive electrode 202 which is associated with a plurality ofactive electrodes disposed at the distal end of the body. The singlepassive electrode 202 is positioned at the distal end 196 of thecatheter body in closely spaced relationship relative to the activeelectrodes. In one embodiment the single return/passive electrode 202(see FIG. 13A, 14A) may be a unitary conductive ring positioned at thedistal end of the catheter, completely of partially surrounding thedistal end, with a surface area being substantially larger than that ofany of the active delivery electrodes 192. It should be noted howeverthat other shapes/forms/designs of the passive electrode are within thescope of the invention.

In an alternate embodiment (see FIG. 14 B) the conductive ring at thedistal end of the catheter can be separated into a plurality of segments205 forming multiplicity of return/passive electrodes 194 juxtaposedwith individual active electrodes 192. These electrodes are in the formof metal sections/inserts electrically insulated from each other andcompletely of partially surrounding the distal end periphery. In thismanner multiple bipolar tissue cutting segments are formed throughentire cross-section of the tool 190.

The electrodes are positioned at the distal end, so that the electriccurrent alternating between electrodes destroys the occlusion in contactwith the electrodes. Because RF energy is delivered by means of electriccurrent alternating between electrodes spaced/separated from inner areasof the blood vessel walls, application of RF technology provides highersafety compare to other methods. Therefore, the possibility of damagingadjacent walls/tissues of blood vessels is minimized.

In a manner previously discussed, detector and/or sensor 196 can beprovided at the distal end of the catheter for determining physical andchemical composition of the occlusion and by means of the computer ormicrochip of the control unit to adjust functionality of RF emitters.

The embodiment of FIGS. 9 and 10 was discussed with the source(generator) of ultrasound energy being disposed at the proximal end ofthe catheter. However, use of other energy generators is also within thescope of the invention. For example, the catheter can be provided with acavitation source disposed at the distal end to deliver cavitation wavesto be used in the intrabody surgery. In use the catheter passesthrough/positioned within the blood vessels (veins or arteries), so thatsuch waves destroy or affect a soft tissue or an organ in a certaindesirable way through mechanically or chemical-mechanical propertiesand/or forces. Outlets emitting cavitation energy can be added to thedistal end of an existing catheter.

According to one embodiment of the invention the cavitation energyoutlets are positioned on the outer diameter of the catheter tip anddisposed at the longitudinal axis passing through the catheter. Thisfacilitates focusing the cavitation waves at the central area of theocclusion. In this arrangement while the occlusions destroyed, the riskof damage to the blood vessel walls is substantially reduced orminimized.

As previously discussed, detector and/or sensor are provided at thedistal end of the catheter capable determining physical and chemicalcomposition of the occlusion and by means of the computer or microchipof the control unit to adjust performance of the cavitation energyoutlets.

As illustrated on FIG. 16A a distal end 220 of a guidewire 210 caninclude a bend or curved portion which facilitates navigation of theguidewire in vasculature. Although various angles of inclination of thedistal end to the remaining part of the guide wire are contemplated, inthe preferred embodiment the distal end 210 is inclined at about30-degree angle.

During the atherectomy procedure a guide wire is first installed intothe vein or artery from the entre point of the patient body till thetargeted occluded area of the targeted blood vessel. Such guidewire isdesigned to be thin and easy to pass within the blood vasculature.However, the longitudinal movement of the guidewire within the vessel isexecuted by the surgeon by pushing the guidewire forward along the bloodvessel. For this movement to occur the guidewire must have certainstiffness which keeps it straight and prevent its coiling within theblood vessel. However, such stiffness in turn complicates the guidewirepassing through the difficult vasculature with close to 90 degree orabuse angle of vessel curvature. Turning now to FIG. 16A showing thatthe very end section of the guidewire 220 can be bent to an optimumangle which may facilitate the guidewire passing through difficult anglevasculature. Surgeon can combine pushing of guidewire and rotating it sothat the bended end of the guide wire may have a higher chance to slideinto the difficult angle vessel while the straight end guidewire wouldjust stop by pushing into the vessel wall. FIG. 16B shows a prior artstraight guidewire inserted through the bore or lumen of a blood vessel232 to cause a stop at the vessel wall making a sharp 90-degree turn.The bended end guidewire is utilized by the invention to facilitate thepassing the sharp bend vascularity by providing an optional sidedirection for guide wire pushed forward by the surgeon. FIG. 16Cillustrates a specific application of this feature of the invention,wherein 90-degree bended tip of the guidewire 220 is successfully pushedthrough by a main straight portion of the guidewire 210 through a 90degree turn in vasculature.

As illustrated on FIG. 17 a hollow guide wire 210 can also include astring 212 attached to the exterior part of the distal end 214. Asfurther illustrated, the string 212 enters into the internal hollow partof the guidewire through a hole 216 located at predetermined optimaldistance from the distal end. In this embodiment by pulling the string212 an operator can remotely manipulate and/or bend the distal area ofthe guide wire 210 to an optimum angle thus targeting the distal endinto required direction within the patient body lumens.

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 21. A catheter assembly in combination with a radiofrequency(RF) electrosurgical instrument, said catheter assembly comprising: acatheter body having a substantially hollow interior and extendingbetween proximal and distal portions; a vacuum source disposed at thedistal end of the catheter to develop a low-pressure zone within thehollow interior of the catheter; multiple active electrodes disposed ata front end of said distal portion of said body for transmittingelectrical signals so as to produce electrosurgical effects adjacent tosaid active electrodes for tissue cutting; and at least one passiveelectrode disposed at said front end of said distal portion of said bodyin closely spaced relationship relative to said active electrodes, eachsaid at least one passive electrode including a passive tissue contactsurface having an area greater than that of an active tissue contactsurface of said corresponding active electrodes, said active electrodesand said at least one passive electrodes optimally cover a predeterminedablation area; wherein said electrodes are spaced from inner walls ofsaid substantially hollow interior, openings provided to aspirate debrisof ablation into and through the hollow interior of the body by thelow-pressure zone.
 22. The catheter assembly in combination with aradiofrequency electrosurgical instrument of claim 21, wherein said atleast one passive electrode is associated with said plurality of activeelectrodes disposed at a distal end of a body, said at least one passiveelectrode is a unitary conductive ring surrounding the distal end, saidconductive ring having a surface area substantially larger than that ofany of said active electrodes.
 23. The catheter assembly in combinationwith a radiofrequency electrosurgical instrument of claim 22, whereinsaid conductive ring is separated into a plurality of segments formingmultiple passive electrodes juxtaposed with said active electrodes. 24.The catheter assembly in combination with a radiofrequencyelectrosurgical instrument of claim 22, wherein said multiple electrodesare in the form of metal inserts electrically insulated from each otherand surrounding the distal end periphery.
 25. The catheter assembly incombination with a radiofrequency electrosurgical instrument of claim22, further comprising at least one sensor provided at the distal end ofthe catheter for determining physical and chemical composition of theocclusion and by means of the computer or microchip of the control unitto adjust functionality of RF emitters.
 26. The catheter assembly incombination with a radiofrequency electrosurgical instrument of claim25, further comprising a control unit which generates controllingsignals adjusting tissue cutting characteristics, wherein said controlunit is associated with computer or microchip.
 27. The catheter assemblyin combination with a radiofrequency electrosurgical instrument of claim26, wherein said at least one sensor provided to emit and receivevarious signals (optical, electromagnetic, acoustical, capacitancemeasuring) capable of detecting composition parameters of the occlusion,and to allow said control unit to generate controlling signalscontrolling the tissue cutting operation, so that as said parameters aredetected within the intrabody occlusion by said at least one sensor thecontrol unit generates controlling signals to adjust functionality of RFemitters.
 28. The catheter assembly in combination with a radiofrequencyelectrosurgical instrument of claim 27, wherein said at least one sensoris located at of said distal portion of said body able to determinephysical and chemical composition of the occlusion.
 29. The catheterassembly in combination with a radiofrequency electrosurgical instrumentof claim 28, wherein said computer or microchip associated with thecontrol unit receives and analyzes information/data obtained by said atleast one sensor and generates signals to adjust functionality of RFemitters.